Crowbar circuit in wind power grid low voltage ride through

The principle of DFIG wind power generation system is analyzed and the mathematic model is developed. The function of the active Crowbar in LVRT is studied and the parameters of the active Crowbar are given. The simulation result shows that the DFIG system with active crowbar can protect converter against overvoltage and over current. Finally, main power circuit and driving circuit of the active Crowbar is designed. A VSG (Voltage Sag Generation) based on resistor is built. The corresponding experiment is done on the 90kWDFIG experimental platform. The LVRT scheme based on the active Crowbar is studied through experimentation. The experiment result shows that Crowbar is necessary for improving LVRT capability of DFIG wind power generation system and LVRT scheme based on the active Crowbar is effective.